Problem: Simplify the following expression: $t = \dfrac{-10r}{6} + \dfrac{-10r}{6}$
Explanation: Since the expressions have the same denominator we simply combine the numerators: $t = \dfrac{-10r - 10r}{6}$ Combine like terms: $t = \dfrac{-20r}{6}$ Simplify by dividing numerator and denominator by 2: $t = \dfrac{-10r}{3}$